Method of producing reinforced seamless-matrix tubes



J. P. SMITH Jan; 24, 1939.

METHOD OF rnonucme REINFORCED SEAMLESS-MATRiX TUBES 2 Sheets-Sheet Original Filed June .8, 1935 I lllllldvl IIPL jade Jan. 24, 1939.

J. P. SMITH METHOD OF PROD CING REINFORCED sEAMLEss-MATRIx TUBES Original Filed June 8, 1935 2 Sheets-Sheet 2 1 I 4 \\M\\\\\\\ \\\\\\A g 7% lllllllllllllllllllllllllllll lb Patented Jan. 24, 1939 TUNI'TIED STATES PATENT OFFICE- METHOD OF PRODUCING- REINFORCED SEAMLESS -MATB1X TUBES John Paul Smith, Chicago, 111., assignor to The Vishing Corporation, Chicago, 111., a corporanon of Virginia Original application June 8,1935, SeriaiNo. 25,888. Divided and this application June 22,

1938, Serial No. 86,638

12 Claims. (Cl. 93- -94) gins are'pasted together, the paper is thoroughly impregnated with a cellulose derivative, either 15 before or after it is formed into a tube, and the formed and pasted tube is drawn through a precipitating bath, or a precipitating and regenerating bath, according to the nature of the cellulose derivative employed. If the cellulose de- 20 rivative employed be a viscose solution, the

formed and pasted tube is drawn through a precipitating and regenerating bath which converts the cellulose derivative into cellulose, or cellulose hydrate; and the tube then is preferably drawn through a purifying water bath, and then through a water-bath containing a small percentage of a hydroscopic agent, such as glycerine. The tube is then dried preferably by passing it in inflated condition through a heated drying chamber. 30 If the cellulose derivative employed be cellulose ether, the formed and pasted impregnated tube is drawn through a precipitating bath and the cellulose derivative ,is precipitated. Thereafter, the tube may be subjected to purifying and 5 drying operations. In this case, the cellulose ether forms the seamless matrix. In both illustrations given, the paper tube, thoroughly imbedded in the matrix, serves as a reinforcement. The paper strip may be coated on one or both 40 sides with a solution of the selected cellulose derivative. In any case, it should be used in suitable condition and volume to, thoroughly impregnate the paper and form-iilmsat the surfaces of the paper. 45 While the paper strip may have the cellulose derivative coating-applied thereto prior to forming the strip into a tube and pasting its overlapping margins together, the coating may be applied after the tube has been formed and 50, pasted. In either event, it is preferred to draw the coated tube continuously through a precipitating medium, or through a precipitating and regenerating medium, thence through a purifying progressivelyflnto tubular form and effect the pasting operation of the margins of the tube as the tube formation takes place.

I have found, for example, that it is possible to apply to a thin, bibulous strip of paper of 5 fragile character a viscose coating, and pass the coated strip, formed into a tube, with the margins pasted together, through a coagulating and regenerating bath, thence through a purifying bath, thence through a bath containing a small percentage of glycerine, and finally through a drier. A thin, fragile strip of paper, with such a coating applied, may be subjected to a continuous drawing operation of the character stated.

. My preferred practice, more specifically stated,

is to draw a strip of paper from a-roll, subject it to curvature about a longitudinal axis to form a tubewith overlapping longitudinal margins, apply a strip of viscose paste to the underlying margin, pass the tubular formation thr ugh a forming. ring which effects pasting the argins, thence through a viscose-coating ring which applies a coating to the outer surface of the tube,

. pass the coated tube (over a depending man- 'drel) downwardly into a coagulating and regenerating bath, thence about a roller in the lower portion of the bath, and thence upwardly and then through additional baths, one of which I may ,be a purifying bath and another a bathcontainlng a small percentage of glycerine. The paper tube, now bearing a regenerated cellulose coating, may be passed directly through a drier; or, it may be stored on rolis, or otherwise, and passed from the storage member through a drier. 3 5

. Finally, the dried, coated tube may be cut into desired lengths. Such tubes may serve as containers for sausages, meats, fruits, or other articles of food, or for any desired purpose. Tubes produced in this manner are tough'andstrong. 40 They may be made tran'slucent or semi-transparent; or they may be made opaque, if desired. Where, from the nature of the cellulose derivative,.precipitation by means of an acid or an alkali is not required, the tubing may be subjected to a drying operationto remove the organic solvent. Solutions of cellulose ethers may be prepared by known processes. Reference is made to 'my application Serial Number 43,409, filed October 3, 1935, for a more complete description of the so use of cellulose ethers in producing reinforced seamless matrix tubes, as a modification of the present invention. bath, and f nally through a drier; and, in this operation, to form successiveportions of the strip,

The accompanying drawings illustrate the process which is preferred.' In this process. a s5 -may be produced; and the tubing mayyafterwards, be cut into suitable lengths for use.

In the drawings, which are largely diagrammatic, Fig. 1 is a side elevational view of apparatus suitable for the practice of the improved process, the drier being shown brokenly' and in section; Fig. 2, a broken plan sectional view taken as indicated at line 2 of Fig. 1. and illustrating the manner in which seam-paste is applied to one margin of the paper strip; Fig. 3, a sectional view of the improved tubing; Fig. 4, a broken vertical sectional view on an enlarged scale showing a mandrel and attendant parts employed in the apparatus; and Fig. 5,-a similar view showing the lower portion of the same mandrel and illustrating its relation to the precipitating bath.

For convenience, the preferred method, in which a solution of viscose is employed, will now be described.

In the illustration given, A designates a frame; B, a tubular mandrel; C, a strip of fabric, such as thin paper, which is taken from a roll and formed into a tube C; D, a precipitating tank into which the mandrel B depends; E, a roller journaled in-the lower portion of the tank D, about which the tube passes; F, a driven roll about which the tube passes as it emerges from the bath D; G, a tank which may, if desired, contain additional precipitating liquid; G, a purifying water bath; G, a final water bath containing a small percentage of glycerine; H, a lower series of rolls mounted in the lower portions of the last-mentioned tanks; I, an upper series of driven rolls mounted at considerable distance above the baths; J, a motor which, through the medium of suitable gearing J, drives the feed rolls mentioned and also drives pumps K and L which serve to deliver the viscose solution to a seam-pasting device K'wand an annular coating device L, respectively; M, a forming-ring through which the tube passes from the pasting deviceK' to the coating device L, the margins of the strip being firmly pasted together before the coating device is reached; and N, a drying device through which the tubing is passed continuously after leaving the bath (3, it being noted that the section of the tubing passing through the drier is kept in inflated condition by means of an elongated isolated air body which is maintained in that portion of the tubing which is within the drier.

In my above-noted Patent No. 2,105,273, apparatus corresponding with that shown in the drawings of the present application is fully 11- plication.

The mandrel B is suitably supported by a bracket l and depends into the precipitating tank D, which, in the case of the use of viscose, contains also a regenerating agent adapted to onvert the precipitated viscose into regenerated cellulose. The fabric strip C is drawn from the roll C and passes downwardly about the mandrel and is curved into approximately tubular form, as shown in Fig. 2. The mandrel carries an adjustable member 2 adapted to serve as a bearing for one marginal portion of the strip. The member 2 is equipped with a gauge 2 which is of suitable form to hold the other margin of the tubing away while paste is being applied to the first-mentioned margin. The device K is in the form of a hollow head 3 w th which communicates a pipe 3 through which cellulose ether paste is delivered. The head 3 has a flat end surface provided with a slot-like orifice (not shown) through which the paste exudes as the Fig. 4 and then downwardly through the precipitating bath D and about the roller E. At this point, the tube is flattened and temporarily closed, so that it will support an internal bath 4, as shown in Fig. 5. The bath in the tank is designated 5. Preferably the liquid head within the tube C is such as to counterbalance the external pressure caused by the bath 5.. In fact, it is preferred to have the levelof the internal bath slightly above that of the external bath.

Precipitating and regenerating fluid is supplied to the tank D in any desired manner. Precipitating and regenerating fluid is supplied to the interior of the tubing (3 by means of an ingoing tube, 6 and an outgoing tube 1. The lower terminus of the tube 6 is slightly below the lower end of the mandrel, as appears in Fig. 5. Attached to the lower end of the mandrel is a blade 8 which tapers downwardly, but which widens downwardly also. blade is to cause lateral extension and flattening of the tube as the tube approaches the roller E shown in Fig. 1.

The lower end of the tube I depends into a cup 9 which is supported 'on a bracket 9 carried by the mandrel. The upper end of the cup 8 determines the level of the internal bath 4. A vacuum is applied to the tube to continuously withdraw liquid from the internal bath as it overflows into the cup 9.

Details of the construction of the mandrel and attendant part's are unimportant for the purpose of the present application.. It may be stated, however, that the section i0 01' the mandrel which appears in Fig. 4 is provided with circular ribs l0 which serve to space the tubing C from the mandrel. The forming ring M is located slightly below the upper rib ill and the bore of the ring 7 is smallest at the central portion, the end po'rtions of the bore'fiaring. The eilfect is to apply a wiping pressure to the seam as it passes through the ring M, but without causing the tubing to bind against the mandrel.

' Briefly stated, the process is as follows: the strip C is taken from a roll 0' and passed arolmd guide rods located a considerable distance, preterably from 5 to 15 feet above the upper end of the mandrel. The paper strip is moderately tensioned in its passage about the guides mentioned, and is suspended in such manner that the paper may be caused to assume tubular form without objectionable strain as the paper passes down- The purpose of the wardly about the mandrel. The manner in which the paper is led from the roll C and gradually brought into tubular form in practically free condition in descending to the mandrel contributes to the success of the process. As the tube moves downwardly continuously past the seam-pester. shown in Fig. 2, a strip of paste is applied to one margin of the strap,the other margin is then brought into overlapping relation, and the pasting operation is completed while the tube passes through the forming ring M. The tube continues downwardly through the annular paste-applying device L, where a solution of viscose is applied. This material is sufficiently fluid to readily coat the external surface of the tubing. A measured supply of material is constantly pumped to the coating-applying device L' through pipe I i. The supply is sumcient to not only thoroughly coat the paper of the tube, but also cause the paper to become thoroughly impregnated. In the in? terval elapsing while the coated tube is passing from the coating device L to the bath in the tank D, the paper becomes well saturated with the viscose. The tubing then passes through the precipitating and regenerating bath I which contains suitable precipitating and regenerating agents,.such as sodium sulphate and sulphuric acid. During passage of the tube through this bath, the viscose is precipitated and then regenerated. If desired, the regenerating action may be completed in a subsequent bath. Bearing in mind that the solution contacts and surrounds the individual fibres in the paper, it will-,be understood that because the precipitation and regeneration occur in situ, the eifect is to form a seamlessregenerated cellulose matrix in which the reinforcing fibre of the paper is uniformly imbedded. Of course, where cellulose ether is used in lieu of viscose, cellulose ether as such forms the seamless matrix.'

Preferably, in the viscose process, viscose is employed as a paste for the joint. in the paper tube as well as for forming the seamless matrix which forms a part of the composite tube. Where the ether process'is employed, cellulose ether takes the place of viscose in these operations.

Any suitable precipitating and regenerating compound may be employed in the bath in the tank D. A bath containing about 3V %-12% H2304 and about %-l5% sodium sulphate (or 10%-20% ammoniumsulphate) is very satisfactory. I f sulphuric acid shall be employed alone at the outset, sodium sulphate will form until a suitable balance is established. In manufacturing a reinforced seamless matrix tube from thin paper in accordance with the viscose process, it is preferred to use a coagulating and regenerating bath comprising about 16%-18% ammonium sulphate and about 2% -4% sulphuric acid in water. It has been found that such a bath, while giving fairly rapid regeneration in the tank D, avoids any violent evolution of gases, and thus tends to the production of a uniform regenerated cellulose matrix coating. .Ordinarily. I temperature of about 33 C. in the bath is desirable. If

the temperature be increased substantially, the

acidity may be lowered advantageously.

Ordinarily the application of a single coating suflices, since the cellulose derivative solution will pass readily through the fabric and'coat all ilbres,

so that, in any event, the interior surface as,

well as the exterior surface becomes coated. A

less desirable method is to apply the cellulose derivative coating to the fabric strip before the latter is formedinto a tube.

Referring to Fig. 3, the paper tube .0: is shown as having an overlap seam designated 12 The cellulose ether matrix is designated l2. It may be understood as being practically coincident with the paper fabric, by thickening the wall of the tube, thoroughly imbedding the fibres ofthe paper, sealing the seam of the tube, and at the same time providing inner and outer coatings for the paper. This will be true, even though the solution be applied (in the required amount) to one surface of the tube only, but, of course, the coating may be thickest on the surface to'which the coating is applied. I

A bath of the character specified above. employing 2%-4% sulphuric acid, works very well in dealing with paper havinga thickness of,-say, about .00 However, the acidity and temperature of the bath may be varied within rather wide limits. It is possible to obtain substantially complete regeneration within the bath D by employing an. acidity from about 3 to about 11% sulphuric acid, depending upon the temperature of the bath, the thickness of the matrix, the rate of drawing. etc. As known in the art, other coagulants and other acids may be employed in pregnating .with a cellulose derivative a thin- 2. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a process which comprises coating and forming a tube progressively' from a tissue of vegetable fibre, the coating-being a cellulose derivative; and passing the coated tube progressively, as formed, downwardly about a mandrel through a precipitating bath and afterwards drying the tube.

- 3. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a'process which comprises progressively and continuously forming a cylindrical tube from a tissue of long fibers and coating and thoroughly impregnating the tube with a cellulose derivative; and continuously drawing the openly distended tube as coated downwardly into a precipitating bath, and thence upwardly out of the bath in flattened condition and subsequently through a purifying bath. 1

.4. In the manufacture of reinforced seamless matrix tubes from a cellulose derivative, a process which comprises: drawing 'a thin paper tube thoroughly impregnated with a cellulose derivative downwardly through an external precipitating bath while maintaining an internal liquid headwithin the distended tube which is opposed to and greater than the head of pressure exerted upon the tube by the external bath.

5. A procas as specified in claim 4, as prac-' ticed by passing the tube, in flattened condition, about a transverse guide in the lower portion of the external bath and leadingthe tube therefrom upwardly out of the external bath.

6. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a process whichcomprises: supporting and forming from a thin paper strip a tube having a substantially upright axis, the tube being formed with mar-' gins adapted to overlap; progressively feeding the tube downwardly through a precipitating bath; applying a strip of paste to a margin during the feeding of the strip; progressively completing the pasting by applying pressure to the overlapping margins; and progressively coating and impregnating the tube with a cellulose derivative in the course of the passage of the tube to the precipitating bath.

7. In the manufacture of reinforced seamless matll'x tubes, a process which comprises drawing a thin fabric tube through a coagulating and regenerating bath while applying a viscose coating to the tube as it approaches the bath; and drawing the tube from the regenerating bath through a subsequent purifying bath.

8. A process as specified in claim '7, in which the viscose coating is applied at a' substantial distance away from the bath and during the passage of the tube through the atmosphere.

9. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a process which comprises: passing a thin-walled vegetable fibre tube, thoroughly impregnated with a cellulose derivative, downwardly through an external precipitating bath which affords a given head while maintaining said tube distended by internal precipitating bath which exerts a head of pressure opposed to and different from that of the external bath.

. 10. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a process feeding the tube distended openly as it is formed into a precipitating medium and eflecting precipitation of the impregnating material.

12. In the manufacture of reinforced seamlessmatrix tubes from a cellulose derivative, a process which comprises: continuously advancing 9. cylindrical fabric strip having overlappedmargins; applying a cellulose derivative so as to coat and penetratesaid advancing fabric strip; and continuously and progressively precipitating the cellulose derivative in a precipitating medium while maintaining the strip in openly distended tubular form.

' JOHN PAUL 3mm. 

